shinydo::pauseAndThinkAboutIt(seconds = 15)
message('Share your ideas via the common chat.')

shinydo::runInternalApp(
  appName = 'googleTrendIndex_V1', 
  display.mode = 'showcase'
)

shinydo::pauseAndThinkAboutIt(seconds = 15)
message('Share your ideas via the common chat.')

shinydo::runInternalApp(
  appName = 'shinyModuleDemo', 
  display.mode = 'showcase'
)

exampleModuleUI <- function(id, label = "Counter") {
  # All uses of Shiny input/output IDs in the UI must be namespaced,
  # as in ns("x").
  ns <- NS(id)
  tagList(
    actionButton(ns("button"), label = label),
    verbatimTextOutput(ns("out"))
  )
}

exampleModuleServer <- function(id) {
  # shiny::moduleServer() wraps a function
  # to create the server component of a module.
  moduleServer(
    id,
    function(input, output, session) {
      count <- reactiveVal(0)
      observeEvent(input$button, {
        count(count() + 1)
      })
      output$out <- renderText({
        count()
      })
      count
    }
  )
}

shinydo::runInternalApp(
  appName = 'googleTrendIndex_V2', 
  display.mode = 'showcase'
)

plotTrendIndex = function(date, close, smoother, smootherSpan){
    # Plot the trend index
    color = "#434343"
    par(mar = c(4, 4, 1, 1))
    plot(x = date, y = close, type = "l",
         xlab = "Date", ylab = "Trend index",
         col = color, fg = color, col.lab = color,
         col.axis = color)
    # Optionally, display smoother
    if(smoother){
        smooth_curve <- lowess(x = as.numeric(date),
                               y = close, f = smootherSpan)
        lines(smooth_curve, col = "#E6553A", lwd = 3)
    }
}

indexTrendModuleUI <- function(id, searchEngine, choices) {
    # All uses of Shiny input/output IDs in the UI must be namespaced,
    # as in ns("x").
    ns <- NS(id)
    tagList(
        titlePanel(sprintf(fmt = "%s Trend Index", searchEngine)),
        sidebarLayout(
            sidebarPanel(

                # Select type of trend to plot
                selectInput(inputId = ns("type"),
                            label = strong("Trend index"),
                            choices = choices,
                            selected = "Travel"),

                # Select date range to be plotted
                dateRangeInput(inputId = ns("date"),label =  strong("Date range"),
                               start = "2007-01-01", end = "2017-07-31",
                               min = "2007-01-01", max = "2017-07-31"),

                # Select whether to overlay smooth trend line
                checkboxInput(inputId = ns("smoother"),
                              label = strong("Overlay smooth trend line"),
                              value = FALSE),

                # Display only if the smoother is checked
                conditionalPanel(
                    condition = sprintf(fmt = 'input["%s"] == true', ns("smoother")),
                    sliderInput(inputId = ns('smootherSpan'), label = "Smoother span:",
                                min = 0.01, max = 1, value = 0.67, step = 0.01,
                                animate = animationOptions(interval = 100)),
                    HTML("Higher values give more smoothness.")
                )
            ),

            # Output: Description, lineplot, and reference
            mainPanel(
                plotOutput(outputId = ns("lineplot"), height = "300px"),
                textOutput(outputId = ns("desc"))
            )
        )
    )
}


indexTrendModuleServer <- function(id, trend_data) {
    # moduleServer() wraps a function to create the server component of a
    # module.
    moduleServer(
        id,
        function(input, output, session) {
            # Subset data
            selected_trends <- reactive({
                req(input$date)
                validate(need(!is.na(input$date[1]) & !is.na(input$date[2]), "Error: Please provide both a start and an end date."))
                validate(need(input$date[1] < input$date[2], "Error: Start date should be earlier than end date."))
                trend_data %>%
                    filter(
                        type == input$type,
                        date > input$date[1] & date < input$date[2]
                    )
            })

            # Create scatterplot object the plotOutput function is expecting
            output$lineplot <- renderPlot({
                plotTrendIndex(
                    date = selected_trends()$date,
                    close = selected_trends()$close,
                    smoother = input$smoother,
                    smootherSpan =  input$smootherSpan)
            })

            # Pull in description of trend
            output$desc <- renderText({
                'The data is a randomly generated place holder.'
            })
        }
    )
}

shinydo::runInternalApp(
  appName = 'googleTrendIndex_V3', 
  display.mode = 'showcase'
)

# Get started
install.packages('shinydo')
vignette(package = 'shinydo', 'shinydo')
shinydo::showPresentation()

# Run the app
shinydo::startTrendIndexDashboard ()

# Query documentation
?shinydo::getTrendIndexData
?shinydo::plotTrendIndex

# Use key functions
trend_data = shinydo::getTrendIndexData(searchEngine = 'Google')
trend_data = subset(x = trend_data, subset = type == 'A')
shinydo::plotTrendIndex(date = trend_data$date, 
                        close = trend_data$close, 
                        smoother = TRUE, 
                        smootherSpan = 0.3)

packageFolder = file.path(tempdir(), 'demoPackage')
devtools::create(path = packageFolder, open = FALSE)

#' Plot trend index
#'
#' Plot trend index as a time series and optionally a smoothed version.
#'
#' @param date A `Date` vector of same length as `close`.
#' @param close Index value at close time as a `numeric` vector of same length as `date`.
#' @param smoother Should a [stats::lowess()] smoothed version of the trend index
#' be plotted as well? Either `TRUE` and `FALSE`.
#' @param smootherSpan the smoother span. This gives the proportion of points in
#' the plot which influence the smooth at each value. Larger values give more
#' smoothness.
#'
#'
#' @return Nothing silently.
#' @export
plotTrendIndex = function(date, close, smoother, smootherSpan){
    # Plot the trend index
    color = "#434343"
    par(mar = c(4, 4, 1, 1))
    plot(x = date, y = close, type = "l",
         xlab = "Date", ylab = "Trend index", col = color, fg = color, col.lab = color, col.axis = color)
    # Optionally, display smoother
    if(smoother){
        smooth_curve <- lowess(x = as.numeric(date), y = close, f = smootherSpan)
        lines(smooth_curve, col = "#E6553A", lwd = 3)
    }
}

# Be in the project directory
setwd(packageFolder)
# creates and opens R/myNewFunction.R
usethis::use_r(name = "myNewFunction")   
# creates and opens tests/testthat/test-myNewFunction.R
usethis::use_test(name = "myNewFunction") 

test_that("multiplication works", {
    expect_equal(2 * 2, 4)
})

test_that("myNewFunction works", {
    expect_equal(myNewFunction(wellChosenInput), expectedOutput)
    expect_error(myNewFunction(wrongInput), 'Error message')
})

devtools::document()
devtools::build()

#' Get ui and server functions
#'
#' Build a ui & server pair for [shiny::shinyApp()].
#'
#' @param theme Name of a Shiny theme as listed by [shinythemes::shinythemes].
#' @template searchEngines
#'
getUi = function(searchEngines, theme = "lumen"){
    fluidPage(theme = shinytheme(theme = theme),

              lapply(
                  X = searchEngines,
                  FUN = function(searchEngine, choices){
                      indexTrendModuleUI(id = searchEngine,
                                         searchEngine = searchEngine,
                                         choices = choices)
                  },
                  choices = unique(generateRandomTrendIndexData()$type)
              )

    )
}

#' @rdname getUi
getServer = function(searchEngines){
    function(input, output) {
        for (searchEngine in searchEngines){
            indexTrendModuleServer(
                id = searchEngine,
                trend_data = getTrendIndexData(searchEngine = searchEngine)
            )
        }
    }
}

#' Start the trend index dashboard
#'
#' Explore the trend index data for various search engines
#'
#' @template searchEngines
#' @inheritParams shiny::shinyApp
#'
#' @export
#'
startTrendIndexDashboard = function(
    searchEngines = getSearchEngineNames(),
    onStart = NULL,
    options = list(),
    uiPattern = "/",
    enableBookmarking = NULL){

    shiny::shinyApp(
        ui = getUi(searchEngines = searchEngines),
        server = getServer(searchEngines = searchEngines),
        onStart = onStart,
        options = options,
        uiPattern = uiPattern,
        enableBookmarking = enableBookmarking
    )

}